Modern satellite communication systems provide a robust and reliable infrastructure to distribute voice, data, and video signals for the global exchange and broadcasting of information. These satellite communication systems have emerged as a viable option to terrestrial communication systems for carrying data traffic such as Internet traffic. A typical satellite Internet system comprises subscriber terminals, a satellite, a ground station, and connectivity to the Internet. Communication in such a system occurs along two links: 1) an uplink (or inroute) from a subscriber terminal to the satellite to the ground station to the gateway to the internet; and 2) a downlink (or outroute) from the internet to the gateway to the ground station to the satellite to the subscriber terminal.
Very Small Aperture Terminals (VSATs) are commonly used as subscriber terminals for transmitting and receiving wireless signals on phase modulated carriers in satellite communications systems. On the transmission (inroute) side, a VSAT includes an indoor unit (IDU) for modulating a signal with information, an example of which may be a satellite Internet modem which can be connected to a customer's computer equipment. The VSAT may also include an outdoor unit (ODU) made up of a block upconverter (BUC) for upconverting the frequency band of the signal (e.g., from the L band to a Ka, C, or Ku band), and a parabolic dish antenna for focusing and transmitting the upconverted signal to a satellite. Moreover, the ODU can include low noise block (LNB) converters that work in conjunction with the BUC. The LNB converters make up the receive portion of the radio equipment, and can be used to down-convert received signals (which are high frequency signals in the Ka, C, or Ku band) to the L band.